Field of the Invention
The present invention relates to a processing apparatus such as a cutting apparatus for performing cutting processing or a laser processing apparatus for performing laser processing for a workpiece such as a semiconductor wafer.
Description of the Related Art
In a semiconductor device fabrication process, a plurality of regions are partitioned by scheduled division lines arrayed in a lattice pattern on the surface of a semiconductor wafer of a substantially disk shape, and devices such as ICs or LSIs are formed in the partitioned regions. Then, the semiconductor wafer is divided along the scheduled division lines to fabricate the individual semiconductor devices.
A method of dividing a wafer such as a semiconductor wafer along scheduled division lines is normally performed by a cutting apparatus called dicer. The cutting apparatus includes a chuck table for holding a workpiece such as a wafer, cutting means for cutting the workpiece held on the chuck table, cassette receiving means for receiving a cassette placed thereon and having a plurality of workpieces accommodated therein, unloading and loading means for unloading and loading a workpiece from and into the cassette placed on the cassette receiving means, temporary receiving means for temporarily receiving the workpiece unloaded by the unloading and loading means and placed thereon, and workpiece transport means for transporting the workpiece temporarily placed on the temporary receiving means to the chuck table. The cutting apparatus configured in this manner divides a wafer held on the chuck table into individual devices by cutting the wafer along scheduled division lines by the cutting means (refer to, for example, Japanese Patent Laid-Open No. 2002-66865).
Meanwhile, as another method of dividing a wafer such as a semiconductor wafer along scheduled division lines, a technology for performing ablation processing by irradiating a pulse laser beam of a wavelength having an absorbency to the wafer along scheduled division lines to form laser processed grooves serving as fracture starting points and applying external force along the scheduled division lines along which the laser processed grooves serving as the fracture starting points are formed to cut the wafer has been put into practical use (refer to, for example, Japanese Patent Laid-Open No. 2004-322168). Also a technology for performing ablation processing for a wafer along scheduled division lines to fully cut the wafer along the scheduled division lines has been proposed.
A laser processing apparatus for forming laser processed grooves along scheduled division lines on a wafer such as a semiconductor wafer as described above includes a chuck table for holding a workpiece, laser beam irradiation means for irradiating a pulse laser beam on the workpiece held on the chuck table, cassette receiving means for receiving a cassette placed thereon and having a plurality of workpieces accommodated therein, unloading and loading means for unloading and loading a workpiece from and into the cassette placed on the cassette receiving means, temporary receiving means for temporarily receiving the workpiece unloaded by the unloading and loading means and placed thereon, and workpiece transport means for transporting the workpiece temporarily placed on the temporary receiving means to the chuck table. The laser processing apparatus configured in this manner forms laser processed grooves on a wafer held on the chuck table by irradiating a laser beam along the scheduled division lines on the wafer (refer to, for example, Japanese Patent Laid-Open No. 2004-322168).